Piet van Oostrum <p...@cs.uu.nl> writes: >>>>>> Aaron Brady <castiro...@gmail.com> (AB) wrote: > >>AB> I am writing a mapping object, and I want to ask about the details of >>AB> __hash__ and __eq__. IIUC if I understand correctly, the Python >>AB> dict's keys' hash codes are looked up first in O( 1 ), then all the >>AB> matching hash entries are compared on equality in O( n ). That is, >>AB> the hash code just really narrows down the search. Am I correct? > > The O(1) part is correct. The O(n) is incorrect if n as usual is taken > to be the number of keys in the dict. But it is true if n is the number > of keys in the `bucket' that belongs to the hash value. The average > complexity of looking up a key is O(1).
As all the keys could be in the same bucket, O(n) seems correct to me (with n the total number of keys). -- Arnaud -- http://mail.python.org/mailman/listinfo/python-list
